I never see a proper modern answer for this question. In React native simply put

const scrollRef = useRef(null as FlatList<item> | null);

(replace 'item' with the type of item you are using for your array data)

Then in flatlist put:

        ref={(ref) => {
            scrollRef.current = ref;
        }}

After that it is simple to use a ref:

scrollref?.current?.scrollToEnd(); //for example